The solution is to capture at .
If White tries to escape with , then Black
makes two eyes and lives.
White cannot escape now.
White cannot play inside anymore and Black is alive.
Even with an additional stone helping White to connect, Black lives.
The connection at is a failure, because after
, Black has only one eye.
Directly preventing the stone from connecting is also a mistake. After
, White dies with a farmer's hat big eye dead shape.
If here,
sets up a ko which Black must win in order to live. Since Black can live unconditionally, this is not the best result .